2008 Mac Pro Freezes After Selecting a boot option in Startup Manager
I have a 2008 Mac Pro that boots to a flashing ? folder icon. I cannot boot into Recovery. I can boot into the Startup Manager by holding the Option key. In Startup Manager, a configured hard drive ...
Was there supposed to be more here, @impathegreat? If you can't boot into Recovery, soemething's wrong with the way the drive is formatted. You'd need to create an OSX 10.11 boot disk (or boot USB) or boot the Mac in Target Disk Mode and reformat from there. If there's something damaged with the drive, that process should begin to reveal it.
After selecting the boot option, hold the "Shift" key until you see the white Apple logo. This should boot in Safe mode.
If you cannot get to Safe mode, then there is nothing on the boot disk to work with.
Do you have a bootable external clone backup?
A 2008 Mac Pro should also have the orignal installation DVD you could try booting from that as well, and using Disk Utility from the Utilities Menu.